Gilbert Jack A, Mühling Martin, Joint Ian
Plymouth Marine Laboratory, Prospect Place, Plymouth, UK.
ISME J. 2008 Jul;2(7):790-3. doi: 10.1038/ismej.2008.49. Epub 2008 May 22.
A sequence analysis is described of a fosmid clone from a coastal marine metagenomic library that contains a 16S rRNA gene with high sequence similarity to that of the SAR11 bacterium 'Candidatus Pelagibacter ubique' HTCC1062. The sequence of the fosmid clone was 32 086 bp in length and contained 23 187 bp of the 48-kb hyper-variable region 2 (HVR2) present in the genome of 'Cand. P. ubique'. However, half of the sequences within the HVR2 region of the fosmid clone show little sequence similarity to or have no representative homologues in the genome sequence of 'Cand. P. ubique' HTCC1062. Given their putative functions, the acquisition of these genes suggests that SAR11 could harbour more diverse phenotypes than represented by the 16S rRNA taxonomy. Variation in SAR11 genomes from different locations might explain why SAR11 is abundant in so many diverse marine provinces.
本文描述了对一个来自沿海海洋宏基因组文库的fosmid克隆进行的序列分析，该克隆含有一个16S rRNA基因，其与SAR11细菌“候选嗜甲基菌属嗜甲基菌”HTCC1062的16S rRNA基因具有高度序列相似性。该fosmid克隆的序列长度为32086 bp，包含了“候选嗜甲基菌属嗜甲基菌”基因组中48 kb高变区2（HVR2）的23187 bp。然而，该fosmid克隆HVR2区域内一半的序列与“候选嗜甲基菌属嗜甲基菌”HTCC1062的基因组序列几乎没有序列相似性，或者没有代表性的同源物。鉴于这些基因的假定功能，这些基因的获得表明，SAR11可能具有比16S rRNA分类法所代表的更多样化的表型。来自不同地点的SAR11基因组的变异可能解释了为什么SAR11在如此多不同的海洋区域中都很丰富。
